Little Catherells Hemel Hempstead, Dacorum
11 addresses across 1 postcode (HP1), about 160 m long, classed as a local road. USRN 10310329.
- Sales: 25 recorded sales since 1995; in 2025 the median was £651,000 across 2 sales.
- Prices and rents: A typical home in Dacorum cost £450,935 in August 2026 (+0.1% on a year); private rents averaged £1,613 a month.
- Energy: 6 homes have an energy certificate (C: 4, D: 2).
- Flood: No address on its postcodes is in an area at high or medium risk of flooding from rivers, the sea or surface water.
- Recorded floods: No recorded flood covers the centre of any of its postcodes.
- Radon: Up to 1 to 3% of homes in the 1 km squares around it are estimated to be at or above the radon Action Level.
- Traffic: The busiest counted road within 500 m (0.3 miles), the Minor road, carries 8,437 motor vehicles a day on average (2025).
- Council tax: Most homes around it are in council tax band C; Band D in Dacorum costs £2,409 a year in 2026-27.
- Broadband: Gigabit broadband is available to 100% of premises.
- Transport: The nearest railway station is Hemel Hempstead, about 2.6 km (1.6 miles) away in a straight line.
- Green space: The nearest park or garden is about 770 m (0.5 miles) away.
- Air: Background air pollution in 2024 was 7.9 µg/m³ of nitrogen dioxide and 7.1 of PM2.5, within UK legal limits.
- Height: Its addresses are 145 to 148 m above sea level.
- Noise: 1 of its 11 addresses is modelled at 55 dB or more from road traffic.
- Doctors: The nearest GP surgery is Parkwood Surgery, about 1 km (0.6 miles) away.
- People: About 300 people lived in the census areas around it in 2021; 73% of households owned their home and 35% of adults held a degree or other higher qualification.
- Crime: 60 crimes were recorded within 250 m between September 2025 and August 2026, most often violence and sexual offences.
- Road safety: 1 collision in which someone was hurt was reported on and around it in 2021 to 2025, and it was serious.
£9.99 The Street Dossier Full Report for a home on Little Catherells: its own records, questions to ask the seller and everything on this page, in one PDF. Choose the home
House sales on this street
| Year | Sales | Median price | Lowest | Highest |
|---|---|---|---|---|
| 2025 | 2 | £651,000 | £540,000 | £762,000 |
| 2022 | 1 | £680,000 | £680,000 | £680,000 |
| 2018 | 2 | £600,000 | £600,000 | £600,000 |
| 2015 | 1 | £513,000 | £513,000 | £513,000 |
| 2014 | 3 | £455,000 | £395,000 | £540,000 |
| 2007 | 3 | £380,000 | £320,000 | £425,000 |
| 2006 | 1 | £335,000 | £335,000 | £335,000 |
| 2005 | 1 | £355,000 | £355,000 | £355,000 |
| 2003 | 2 | £297,000 | £269,000 | £325,000 |
| 1999 | 1 | £225,000 | £225,000 | £225,000 |
| 1998 | 4 | £199,750 | £142,500 | £205,000 |
| 1997 | 3 | £139,500 | £121,000 | £165,000 |
| Date | Address | Type | Price | Notes |
|---|---|---|---|---|
| 26 Feb 1996 | 1 HP1 3QB | Detached | £146,000 | |
| 18 Oct 2022 | 2 HP1 3QB | Detached | £680,000 | |
| 16 Aug 2018 | 2 HP1 3QB | Detached | £600,000 | |
| 8 Apr 1997 | 2 HP1 3QB | Detached | £165,000 | |
| 27 Jan 1997 | 3 HP1 3QB | Detached | £121,000 | |
| 23 Jan 2018 | 4 HP1 3QB | Detached | £600,000 | |
| 24 Mar 2006 | 4 HP1 3QB | Detached | £335,000 | |
| 30 Apr 1998 | 4 HP1 3QB | Detached | £142,500 | |
| 17 Oct 1997 | 4 HP1 3QB | Detached | £139,500 | |
| 20 Mar 2025 | 5 HP1 3QB | Detached | £762,000 | |
| 28 Nov 2014 | 5 HP1 3QB | Detached | £540,000 | |
| 31 Oct 2005 | 5 HP1 3QB | Detached | £355,000 | |
| 6 Feb 2003 | 5 HP1 3QB | Detached | £325,000 | |
| 20 Mar 1998 | 5 HP1 3QB | Detached | £199,500 | |
| 24 May 2007 | 6 HP1 3QB | Detached | £425,000 | |
| 9 Jul 1999 | 6 HP1 3QB | Detached | £225,000 | |
| 1 Dec 2014 | 7 HP1 3QB | Detached | £455,000 | |
| 24 May 2007 | 7 HP1 3QB | Detached | £380,000 | |
| 27 Nov 1998 | 7 HP1 3QB | Detached | £200,000 | |
| 24 Nov 2025 | 8 HP1 3QB | Detached | £540,000 | |
| 8 Dec 2014 | 8 HP1 3QB | Detached | £395,000 | |
| 6 Jul 2007 | 8 HP1 3QB | Detached | £320,000 | |
| 17 Apr 2003 | 8 HP1 3QB | Detached | £269,000 | |
| 4 Sep 2015 | 10 HP1 3QB | Detached | £513,000 | |
| 22 Sep 1998 | 10 HP1 3QB | Detached | £205,000 |
House prices and rents in Dacorum
A typical home in Dacorum cost £450,935 in August 2026, 0.1% more than a year before. That is 8% more than five years earlier and 21% more than ten years earlier.
| Home | Typical price, Aug 2026 |
|---|---|
| Detached | £913,529 |
| Semi-detached | £544,712 |
| Terraced | £418,630 |
| Flat or maisonette | £258,834 |
| Bought by a first-time buyer | £364,385 |
Private renters in Dacorum paid £1,613 a month on average in September 2026, 2.5% more than a year before. That is 28% more than five years earlier.
| Home | Average rent a month, Sep 2026 |
|---|---|
| One bedroom | £1,111 |
| Two bedrooms | £1,394 |
| Three bedrooms | £1,677 |
| Four or more bedrooms | £2,316 |
Energy performance certificates
6 homes with a current certificate; median floor area 118 m². Most common: House, detached (6). Built: 1991-1995 (3); 1983-1990 (2); 1976-1982 (1). Tenure at assessment: owner-occupied (6).
Each home's certificates and sales (6 addresses)
Gas and electricity use
Homes with gas used 16,403 kWh of it on average in 2024, 39% more than the district's 11,796 kWh, and 5,534 kWh of electricity, 60% more than the district's 3,461 kWh. There are gas meters for about 100% of the homes.
These are all the homes on the postcode, whatever their size and however many live in them, so they show the kind of homes and heating here rather than what any one home uses. The typical figure is the median: half the homes used less. The district is HP1.
Council tax
What each band costs in Dacorum in 2026-27: Band D £2,409 a year on average, including the police, fire and any county and parish charges.
| A | B | C | D | E | F | G | H |
|---|---|---|---|---|---|---|---|
| £1,606 | £1,873 | £2,141 | £2,409 | £2,944 | £3,479 | £4,014 | £4,817 |
Homes by band in the neighbourhood around this street: most are in band C (41% of about 640 homes).
Planning and heritage
- Conservation area: no postcode centre in this street's postcodes is in one.
- Listed buildings on or by this street: none.
- Article 4 direction (removing permitted development rights): none recorded, though not every council has published theirs.
- Tree preservation orders: none recorded, though not every council has published theirs.
- Green belt: no.
Energy projects nearby
No wind turbine or waste plant within 5 km (3.1 miles), and no solar farm, battery site or other project of 1 MW or more within 2 km (1.2 miles), of the street's postcodes, operating or planned.
Roadworks
No street works under way, planned or finished in the last three months on this street, in permits up to 31 October 2026.
Flood risk
No address in this street's postcodes is in an area at high, medium or low risk of flooding from rivers, the sea or surface water. The rest are in areas at very low risk: less than a 0.1% (1 in 1,000) chance a year.
Rivers and the sea alone: no home is in an area at risk.
High: 3.3% (1 in 30) or more chance of flooding a year. Medium: 1% to 3.3%. Low: 0.1% to 1%. Very low: under 0.1%. The rivers and sea figures allow for flood defences. Counts cover whole postcodes, which can include other streets.
Flood zone for planning: no postcode centre is in flood zone 2 or 3.
Recorded floods
No recorded flood covers the centre of this street's postcodes.
Recorded floods are where floodwater was seen or surveyed after a flood. Many floods were never mapped, an outline over a postcode's centre does not mean every home in it flooded, and homes outside one may have. Ask the seller whether the home itself has flooded.
Coastal erosion
No projected coastal erosion zone is within 1 km (0.6 miles) of the street's postcodes.
Storm overflows
No storm overflow outlet is within 1 km (0.6 miles) of the street's postcodes.
Coal mining
No postcode centre here is in a coalfield: the Mining Remediation Authority records no coal mining risk here.
Radon
The postcode is in a 1 km square with radon potential up to 1 to 3%: up to that share of homes there is estimated to be at or above the Action Level of 200 becquerels per cubic metre. At least part of the square is a radon Affected Area, where 1% or more of homes are.
Radon is a natural radioactive gas from the ground that can build up indoors; long exposure raises the risk of lung cancer. A three-month test with two small detectors is the only way to know a home's level, and a high level can usually be brought down with a sump or better ventilation. UKHSA sells a radon report for a single address from its detailed map at ukradon.org.
Historic landfill
No historic landfill site is within 500 m (0.3 miles) of the street's postcodes.
Height above sea level
The street's 11 addresses are between 145 m and 148 m above sea level (146 m on average).
Broadband
| Postcode | Superfast (30 Mbit/s+) | Ultrafast (300 Mbit/s+) | Gigabit | Below 10 Mbit/s |
|---|---|---|---|---|
| HP1 3QB | 100% | 100% | 100% | 0% |
Getting around
| Nearest | Distance | |
|---|---|---|
| Railway stations | Hemel Hempstead 1.6 million journeys in 2024–25 | 2.6 km (1.6 miles) |
| Berkhamsted 1.3 million journeys in 2024–25 | 4.2 km (2.6 miles) | |
| Apsley 518,000 journeys in 2024–25 | 4.4 km (2.8 miles) | |
| Bus stops | 3 stops within 400 m (0.2 miles), 10 within 800 m (0.5 miles); nearest The Avenue Warners End | 300 m |
| Car parks | Stoneycroft Car Park | 1.1 km (0.7 miles) |
| EV charging points | Osprey Charging Station | 2 km (1.2 miles) |
| Airport with scheduled flights | London Luton Airport LTN | 15.3 km (9.5 miles) |
Local services
| Nearest | Distance | |
|---|---|---|
| GP surgeries | 1 practice within 1.6 km (1 mile); nearest Parkwood Surgery Requires improvement Apr 2026 | 1 km (0.6 miles) |
| Pharmacies | 2 pharmacies within 1.6 km (1 mile); nearest Gadebridge Pharmacy | 820 m (0.5 miles) |
| NHS dentists | 2 practices within 1.6 km (1 mile); nearest Dental Surgery | 460 m (0.3 miles) |
| Hospital | Hemel Hempstead Hospital Requires improvement Jun 2020 | 2.7 km (1.7 miles) |
| Care homes | 1 home within 1.6 km (1 mile); nearest Highview Lodge Requires improvement Jul 2025 | 420 m (0.3 miles) |
| Police station | Hemel Hempstead Police Station | 2.2 km (1.4 miles) |
| Cash machines | The Cooperative Food Warners End, Warners End Cashzone | 1.1 km (0.7 miles) |
Parks and green space
| Nearest | Distance | |
|---|---|---|
| Park or garden | 1 within 800 m (0.5 miles); nearest Unnamed 1.0 ha | 770 m (0.5 miles) |
| Play area | 1 within 800 m (0.5 miles); nearest Unnamed 500 m² | 420 m (0.3 miles) |
| Playing field | 1 within 800 m (0.5 miles); nearest Unnamed 23 ha | 50 m |
| Allotments | Gravel Hill Allotment Gardens 1.6 ha | 1.4 km (0.9 miles) |
Within 800 m (0.5 miles): 1 park or garden, 1.0 hectares in all.
Landmarks
The nearest historic landmark is Gadebridge Roman villa, a scheduled monument, 1.5 km (0.9 miles) east. 1 listed building is within 1 km (0.6 miles).
| Name | What it is | From the middle of the street |
|---|---|---|
| Gadebridge Roman villa | Scheduled monument | 1.5 km (0.9 miles) east |
| Hemel Water Gardens | Registered park or garden, Grade II | 2.4 km (1.5 miles) south-east |
| Name | What it is | From the middle of the street |
|---|---|---|
| Dell Wood | Wood | 720 m (0.4 miles) north-east |
| Catstail Wood | Wood | 950 m (0.6 miles) north |
| Warnersend Wood | Wood | 1 km (0.6 miles) north-east |
| Martins Pond | Lake or reservoir | 1.9 km (1.2 miles) west |
| Hogstrough Dell | Valley | 2.5 km (1.6 miles) north |
| Box Hill | Hill | 2.7 km (1.7 miles) south |
Air quality
| Pollutant | Here | UK limit | WHO guideline |
|---|---|---|---|
| Nitrogen dioxide (NO2) | 7.9 | 40 | 10 |
| Fine particles (PM2.5) | 7.1 | 20 | 5 |
| Particles (PM10) | 11.9 | 40 | 15 |
All three are within the UK legal limits; PM2.5 is above the WHO guideline, as in most towns and cities.
Road and rail noise
| Level | Road traffic | Railways |
|---|---|---|
| 55 to 59 | 1 | 0 |
| Under 55 | 10 | 11 |
1 of the street's 11 addresses is modelled at 55 dB or more from road traffic, above the WHO guidelines.
Climate, daylight and earthquakes
Monthly temperatures and rainfall, sunrise and sunset through the year, and earthquakes recorded nearby since 1970 are much the same across the area, so they are worked out once for Dacorum: see them on the Dacorum page.
Nearest schools
| School | Phase | Ages | Distance | Inspection | Exam results |
|---|---|---|---|---|---|
| John F Kennedy Catholic School Roman Catholic | Secondary | 11–18 | 570 m (0.4 miles) | Report card (May 2026): Curriculum and teaching: Expected standard; Achievement: Expected standard; Attendance and behaviour: Expected standard; Personal development and wellbeing: Strong standard; Inclusion: Expected standard; Leadership and governance: Expected standard; Post-16 provision: Expected standard; Safeguarding standards: Met | GCSE 2026 (provisional): Attainment 8 51.9 (47.9 in 2025 and 50.9 in 2024); 62.9% grade 5+ in English and maths A level 2025: average grade C+; 7.9% AAB or better; progress average |
| Galley Hill Primary School and Nursery | Primary | 3–11 | 800 m (0.5 miles) | No overall grade (Oct 2024, graded inspection without an overall judgement): Quality of education: Good; Behaviour and attitudes: Good; Personal development: Good; Leadership and management: Good | 51% at the expected standard in reading, writing and maths, 5% at the higher standard (2025; 47% in 2024 and 44% in 2023) |
| Micklem Primary School | Primary | 3–11 | 1 km (0.6 miles) | No published inspection | 52% at the expected standard in reading, writing and maths, 0% at the higher standard (2025; 40% in 2024 and 31% in 2023) |
| St Cuthbert Mayne Voluntary Catholic Junior Academy Roman Catholic | Primary | 7–11 | 1.4 km (0.9 miles) | No published inspection | 65% at the expected standard in reading, writing and maths, 13% at the higher standard (2025; 72% in 2024 and 68% in 2023) |
| Laureate Academy | Secondary | 11–18 | 1.5 km (0.9 miles) | Good (Jun 2023, overall grade under the previous framework) | GCSE 2026 (provisional): Attainment 8 42.7 (41.7 in 2025 and 41.7 in 2024); 39.8% grade 5+ in English and maths A level 2025: average grade C+; 13% AAB or better; progress average |
| Oakleaf Primary | Primary | 3–11 | 1.5 km (0.9 miles) | No published inspection | 24% at the expected standard in reading, writing and maths, 3% at the higher standard (2025) |
| Gade Valley Primary School | Primary | 3–11 | 1.5 km (0.9 miles) | No published inspection | 62% at the expected standard in reading, writing and maths, 7% at the higher standard (2025; 69% in 2024 and 64% in 2023) |
| Pixies Hill Primary School | Primary | 4–11 | 1.8 km (1.1 miles) | Good (Apr 2023, overall grade under the previous framework) | 66% at the expected standard in reading, writing and maths, 10% at the higher standard (2025; 70% in 2024 and 67% in 2023) |
| Potten End CofE Primary School Church of England | Primary | 3–11 | 1.9 km (1.2 miles) | No published inspection | 59% at the expected standard in reading, writing and maths, 7% at the higher standard (2025; 60% in 2024 and 66% in 2023) |
| Boxmoor Primary School | Primary | 3–11 | 2 km (1.2 miles) | Good (Mar 2024, overall grade under the previous framework) | 67% at the expected standard in reading, writing and maths, 17% at the higher standard (2025; 57% in 2024 and 62% in 2023) |
| St Rose's Catholic Infant School Roman Catholic | Primary | 2–7 | 2 km (1.2 miles) | No published inspection | None published |
Exam results are from the Department for Education's school performance tables (Explore Education Statistics, Open Government Licence), for all pupils at each school. The middle school in England had 63% at the expected standard at the end of primary school (2025), Attainment 8 of 46.0 at GCSE (2026) and an A level average of C+ (2025). Attainment 8 adds up a pupil's grades in eight GCSEs, with English and maths counted twice (90 is the most), averaged over the school's pupils. Progress 8 compares pupils with others who had the same results at the end of primary school; it is not published for GCSEs in 2025 and 2026, as those pupils sat no primary tests during the pandemic. Small year groups swing from year to year, and figures for very small ones are withheld.
Nurseries and childcare
9 nurseries, pre-schools and clubs within 1.5 km (0.9 miles), the nearest 800 m (0.5 miles) from the middle of the street.
| Provider | Kind | Places | Latest inspection | Distance |
|---|---|---|---|---|
| CoachingMe After School and Holiday Club HP1 3JY | Out-of-school day care | 24 | Not inspected yet | 800 m (0.5 miles) |
| Gadebridge Nursery & Pre-School HP1 3LG | Full day care | 36 | Good (Jan 2023, overall grade under the previous framework) | 820 m (0.5 miles) |
| Bam & Tata's Day Nursery HP1 3LG | Full day care | 55 | Not inspected yet | 820 m (0.5 miles) |
| Micklem After School Club HP1 2QH | Out-of-school day care | 25 | Not inspected yet | 1 km (0.6 miles) |
| Little Acorns Pre School HP1 3QG | Sessional day care | 25 | Good (Jul 2021, overall grade under the previous framework) | 1.1 km (0.7 miles) |
| Woodlands Pre-School HP1 1RZ | Sessional day care | 55 | Good (Sep 2025, overall grade under the previous framework) | 1.3 km (0.8 miles) |
| Bright Horizons Potten End Day Nursery and Preschool HP1 3BN | Full day care | 92 | Good (Jun 2022, overall grade under the previous framework) | 1.3 km (0.8 miles) |
| Good Shepherd After School Club at Oakleaf Primary School HP1 2JU | Out-of-school day care | 40 | Not inspected yet | 1.5 km (0.9 miles) |
| Stagecoach - Gade Valley HP1 3DT | Out-of-school day care (over fives) | Not inspected yet | 1.5 km (0.9 miles) |
Ofsted also registers 841 childminders and 251 home childcarers (nannies) in Hertfordshire. It does not publish their addresses, so they cannot be shown here; the council's family information service lists those taking children.
Food hygiene ratings nearby
| Business | Type | Distance | Rating | Rated |
|---|---|---|---|---|
| Highview Lodge & Day Centre HP1 3SD | Hospitals/Childcare/Caring Premises | 420 m (0.3 miles) | 5 Very good | 3 Sep 2025 |
Crime within 250 m
| Category | Crimes |
|---|---|
| Violence and sexual offences | 25 |
| Anti-social behaviour | 18 |
| Criminal damage and arson | 7 |
| Vehicle crime | 3 |
| Public order | 3 |
| Other theft | 2 |
| Other crime | 1 |
| Possession of weapons | 1 |
Most of these are attached to: On or near Elm Green (23); On or near Maple Green (12); On or near Daggs Dell Road (9); On or near Sandalls Spring (7); On or near Warmark Road (4).
Road safety
1 collision in which someone was hurt was reported on and around the street in 2021 to 2025: 0 fatal, 1 serious and 0 slight, in which 1 person was seriously hurt. 1 involved a motorcyclist; 1 involved a child under 16. Most were on roads with a 30 mph limit.
| Year | Collisions | Fatal or serious |
|---|---|---|
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 0 | 0 |
| 2025 | 1 | 1 |
| Date | Severity | Who was hurt | Road | Conditions |
|---|---|---|---|---|
| 11 Jun 2025 13:15 | Serious | 1 person: 1 motorcyclist, 1 child | Minor road, 30 mph | Daylight |
Only collisions in which someone was hurt and which the police were told about are here: damage-only collisions and near misses are not, and some injuries are never reported. Positions are recorded by the police, usually to within a few metres. Each year's figures are published the following September.
Traffic on nearby roads
The busiest counted road within 500 m (0.3 miles) is the Minor road, with 8,437 motor vehicles a day on average in 2025, 320 m from the street's postcodes.
| Road | Between | Vehicles a day | Lorries | Ten years before | Distance |
|---|---|---|---|---|---|
| Minor road | Not recorded | 8,437 counted 2025 | 2% | 320 m |
Each figure is the annual average daily flow: the motor vehicles passing the count point, both ways, on an average day of the year. A point is counted by hand on a weekday every few years and estimated from the trend on similar roads in between. Lorries are heavy goods vehicles, as a share of all motor vehicles.
People and work
Who lives here
| Around this street | England | |
|---|---|---|
| Median age | 42 | 40 |
| Children under 15 | 21% | 17% |
| Aged 65 and over | 16% | 18% |
Homes
| Around this street | England | |
|---|---|---|
| Owned (outright or with a mortgage) | 73% | 61% |
| Owned outright | 32% | 33% |
| Shared ownership | 0% | 1% |
| Social rented | 14% | 17% |
| Private rented | 13% | 21% |
Work and commuting
| Around this street | England | |
|---|---|---|
| Adults (16 and over) in work | 65% | 57% |
| Unemployment (of those working or looking for work) | 2% | 6% |
| Retired (of adults) | 18% | 22% |
| Long-term sick or disabled (of adults) | 3% | 4% |
| Work mainly from home (of those in work) | 43% | 32% |
| Travel to work by car or van | 53% | 48% |
| By train, Underground, metro or tram | 2% | 4% |
| By any public transport, including bus | 3% | 8% |
| On foot or by bicycle | 1% | 10% |
| Work within 10 km (6 miles) of home (of those who travel to work) | 51% | 65% |
| Work 30 km (19 miles) or more away | 12% | 8% |
Education and languages
| Around this street | England | |
|---|---|---|
| Degree or other higher qualification, Level 4+ (of adults) | 35% | 34% |
| No qualifications | 14% | 18% |
| Apprenticeship as highest qualification | 5% | 5% |
| Main language English (aged 3 and over) | 92% | 91% |
| Cannot speak English well or at all | under 1% | 2% |
Deprivation
The neighbourhood around this street is in decile 8 of 10 on the English Indices of Deprivation 2025, where 1 is the most deprived tenth of England's 33,755 neighbourhoods and 10 the least.
What has changed
Nothing new since the change feed started on 30 October 2026. New sales and energy certificates, and hygiene ratings, school inspections and flood figures nearby, will be listed here as the sources update.
Postcodes on this street
- HP1 3QB: 11 addresses of 12 in the postcode
Nearby streets
Sandalls Spring · Knights Orchard · Elm Green · Daggsdell Road · Whitebroom Road · Polehanger Lane · Lyne Way · Warmark Road · Parklands · Someries Road · Robe End · Daggs Dell Road
What this page cannot tell you
- Whether a particular house is at risk of flooding, subsiding or anything else: the flood map is a model of areas and there is no property-level data here.
- What a home is worth now: sales are historic prices for the homes that happened to sell.
- How safe the street is: crime points are moved to anonymised locations and many crimes are never reported; road collisions count only those in which someone was hurt and the police were told.
- Whether you would get a place at a school: distances are straight lines, not catchments.
- Who lives on the street now: census figures describe the small areas around it in March 2021, during a lockdown.
- How long a journey takes or how often anything runs: transport distances are straight lines to the nearest stops.
- Whether a GP practice is taking new patients, or a dentist new NHS patients.
- How loud a home is inside, or noise from industry, neighbours or smaller airfields: noise figures are models of road, rail and air traffic outside.
How each figure on this page is matched to the street and worked out: methodology.